With the accelerated growth of hyperscale datacenters, the performance demands on Ethernet network infrastructure is increasing exponentially, and customer expectations for high-speed data throughput is at an all-time high. As a result, Bit Error Rate Testers (BERT) have become a cornerstone for physical layer testing, from qualifying bit transmission for fiber optic and copper-wire digital data transmission lines to testing signal integrity. A BERT generates a sequence of bits through a communication channel and the received bits are then compared against the transmitted bits. A Bit Error Ratio (BER) evaluates the full end-to-end performance of a connectivity system and assures communication reliability. The ML4039EN is a 4-channel, 56 GBd PAM4 & NRZ, 400G BERT with a unique crosstalk noise injection capability. It can be used in combination with ML407-PAM for jitter tolerance testing and has a programmable ISI emulator. Real hardware FEC testing is also possible with the versatile ML4039EN.
4-Channel | 56 GBd PAM4 & NRZ | 400G BERT with ISI, JTOL & Crosstalk Noise injection|
4 x 56 GBd NRZ/PAM4 BERT | SSPRQ, PRBS13Q & PRBS31Q | 7-Tap PPG Linear Equalizers | Signal SNR, Histogram and Dynamic FFE | Programmable ISI Emulator to 9 dB | Shallow Loopback Testing | FEC
ML4039EN
ML4039EN 4 x 56 GBd BERT Introduction
The ML4039EN is a full feature 400G BERT that can be configured as a four-channel PAM4 56 GBaud or four-channel NRZ 28/56 Gbps lanes. Also, half rates of 23 to 29 GBd are supported. The transmitters Support all standard test patterns mandated by IEEE and OIF such as PRBS13Q, SSPRQ, PRBS31Q, etc. It is also possible to program the TX to output a user-defined pattern. The ML4039EN is specifically designed to add crosstalk noise with configurable frequency up to 29.6 Gbps for NRZ and up to 29.6 GBaud for PAM4. Additionally, the user can select to programmatically add an ISI channel equivalent to a frequency-dependent attenuator with 1 to 9 dB loss at Nyquist. When used in conjunction with the ML407-PAM clock synthesizer, it can modulate its output pattern with SJ of over 5UI and up to 4 MHz.
Key Features Transmit
Data Rates: 23 – 29 & 46 – 58 GBd
Ability to tune the bit rate in steps of 100 kbps and find the RX PLL locking margin
Independent control of inner eye levels
Up to 0.8 Vppd output swing
Supports Gray coding and polarity inversion Available patterns are:
- PRBS7/9/11/13/15/16/23/31/58 - PRBS13Q, PRBS31Q - SSPRQ - Square wave - Error injection
3-tap Pre- and Post-emphasis
7-tap linear TX FFE
Programmable ISI Emulation
Receive
SNR monitoring over time
PAM4 histogram monitor
PAM4 slicer threshold adaptive
Error-detection on following patterns: - PRBS 7/9/11/15/16/23/31 - PRBS13Q and PRBS31Q
LOS indicators General
API libraries with documentation
LabView sample and Python wrapper available
Shallow Loopback testing
Forward Error Correction (FEC) - Support generation of idle pattern with
RS544/RS528 encoding types - Support FEC decoding on RX and FEC
statistics measurement
Crosstalk Injection - Configurable frequency in the range of 9-
14.2 Gbps and 22-29.6 Gbps for NRZ and 22-29.6 GBaud for PAM4
Same product available in ATE format for Advantest V93K
Target Applications
Production testing of transceivers
Functional and SI testing
JTOL for 26 and 53 GBd receivers
Figure 1: PAM4 eye histogram
Figure 2: RX FFE Taps
Using ThunderBERT GUI both accumulated and instantaneous BER measurements can be monitored.
Block Diagram
SI Channel Emulation The ML4039EN can programmatically emulate the effect of frequency-dependent attenuators with 1 dB up to 10 dB loss at the Nyquist frequency and a frequency roll-off similar to a PCB trace. When it comes to compliance testing on transceivers, more specifically for the stressed input test, this is highly practical. The effects of the different settings are shown in Fig. 5-10, both in eye diagram mode, as well as in pattern view.
Figure 5: 1 dB ISI Channel
Figure 6: 2 dB ISI Channel
Figure 7: 3 dB ISI Channel
Figure 3: BER curves using ThunderBERT GUI
Figure 8: 4 dB ISI Channel
Figure 9: 5 dB ISI Channel
Figure 10: 8 dB ISI Channel
Figure 10: 8 dB
ISI Channel
Figure 4: ML4039EN Block Diagram
Jitter Tolerance Testing The following measurement captures on 26/53 GBd PAM4 show the effects of crosstalk and jitter injection on a clean pattern.
Figure 11: Adding impairments to a 26/53 GBd signal using the ML407-PAM clock synthesizer
Figure 12: JTOL Test Setup
Figure 13: ML407-PAM Clock Jitter Synthesizer
Noise Injection The ML4039EN enables noise injection feature to emulate real-life crosstalk scenarios along with shallow loopback testing. Noise implementation can be done in the form of a continuous interference, burst crosstalk, or single shot noise and can be configured on each channel independently. The shallow loopback function works with a variety of traffic types including unframed PRBS, framed Ethernet and FEC traffic. The following figure depicts a ML4039EN accepting traffic from an external 400G switch, looping the traffic back internally and re-transmitting it back to the RX side of the host.
Figure 14: Shallow Loopback using ML4039EN and 400G switch
Electrical Specifications
Parameter Specifications
Bit Rates PAM4: 23 – 29 GBaud and 46 – 58 GBaud NRZ: 23 – 29 Gbps and 46 – 58 Gbps
TX Amplitude Differential 0 - 800 mVpp
Patterns PRBS7/9/11/13/15/16/23/31/58 PRBS13Q, 31Q and SSPRQ Square wave & user-defined pattern
Linear Range 50 mV – 800 mV
TX Amplitude Adjustment Steps of 2 mV
Pre- / Post-emphasis 6 dB
De-Emphasis Resolution 1000 steps
Equalizing Filter Spacing 1 UI
Random Jitter RMS 230 fs
Rise / Fall Time (20–80%) 12 ps / 14 ps
Coding DFE Pre-coding and Gray coding supported
FEC (up to 400G stripes) KP (100G, 400G) KR (100G)
Return Loss up to 10 GHz < -18 dB
Return Loss (16-25 GHz) < -15 dB
Error Detector input
range 50 mV– 800 mV diff.
TX/RX connectors 2.4 mm connectors (2.92 mm optional)
Clock
Output
Reference
clock Rate dividers 8/16/32/128
Monitor
Clock 156.25 MHz
Clock Input max Up to 2.5 GHz
Clock Input Amplitude 750 mV single-ended
Input Impedance 50 Ω
Ambient Temperature 0-40 °C
Power 110 V, 1.4 A or 220 V, 0.9 A – 50/60 Hz
Mechanical Dimensions
Ordering Information
Recommended Accessories
Please contact us at [email protected].
Option Description
ML4039EN 400G BERT (4 CH 56 GBd NRZ/PAM4)
3YW Total 3-year warranty
CAL Single calibration
3YWC Total 3-year warranty with 3 annual
calibrations
FEC Real hardware FEC
29 2.92 mm connectors
Instruments Recommended Phase matched cable pairs
Alternative Phase matched cable sets
Comments
ML4039EN
standard 8x MLCBPM-2.4-30 2x MLCBPM-2.4-30-8 2.4 mm connector 2x8 channel 30 cm
ML4039EN
standard 8x MLCBPM-2.4-60 2x MLCBPM-2.4-60-8 2.4 mm connector 2x8 channel 60 cm
ML4039EN-29 8x MLCBPM-2.92-30 2x MLCBPM-2.92-30-8 2.92 mm connector 2x8 channel 30 cm
ML4039EN-29 8x MLCBPM-2.92-60 2x MLCBPM-2.92-60-8 2.92 mm connector 2x8 channel 60 cm
The ML4039EN is a benchtop instrument that fits in a 19-inch 2U rack. Two ML4039ENs arranged side by side take up one 2U slot in your rack. MultiLane also supplies the needed brackets.
North America Worldwide Asia
48521 Warm Springs Blvd. Suite 310 Houmal Technology Park 14F-5/ Rm.5, 14F., No 295 Fremont, CA 94539 Askarieh Main Road Sec.2, Guangfu Rd. East Dist., USA Houmal, Lebanon Hsinchu City 300, Taiwan (R.O.C) +1 510 573 6388 +961 81 794 455 +886 3 5744 591
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